Joke: A man walks into a picture framing shop and says: "I'd like a 10cmx10xm frame for my 10cmx10cm picture, but make it negative 12.5cm away from the picture." The shop staff is confused, but makes a wild guess: "So you want a frame with each border 2.5cm on the other side of the picture than it would normally be?" The man just takes a note and goes to another shop.

He collected the wild guesses from various picture framing shops and posted them on twitter, getting a lot of attention on Hacker News as well.

edit: present tense.